Telephone relay or repeater.



L. W. SOUTHGATE.

TELEPHONE RELAY OH R EPEATER.

APPLICATION FILED MAR. 3, 1902.

Patented June 21, 1910.

2 SHEETSSHBET 1.

L. W. SOUTHGATE.

TELEPHONE RELAY OR REPEATER.

APPLICATION FILED MAR. s, 1902.

961,815, Patented June 21,1910.

2 SHEETS-SHEET 2.

1'71, den-tun TJd Tresses fir/.6. i-w of M 7 tours w. sournea'rn, or WORCESTER. MASSACHUSETTS.

TELEPHONE RELAY OR REPIlATER.

Specification of 'Iietters Patent.

Patented June 21, 1910:

Application filed March 3, 1902. Serial No. 96.4255) 'To all uihoni it may concern.

Be it known that 'I, Ijouls W. SoU'rrIoA'rn, a citizen of the United States, residing at W'orcester, in the county of Worcester and It has been proposed by numerous in renters since ,'1S 8 0,to make a telephone rclay or repeater by using an electro-magnct "oilin a first circuit, and a variable reace device or microphone in a second ciret t,--includiiig a new source of electricity, said n'iicroplione being connected to an iron br steel diaphragm or armature mounted in rinse relation ,to the magnet, so that .the microphone will be actuated thereby. lVl-iile it-is possible tomake a telephone relay or repeater of this character, which will am phfy, so far as I am informed and believe, no telephone relay or repeater has yet been brought to such .practical point as to be iwpa'ie of commercial use. The reason of this that the sound vibrations of the luv in" n, voice are made up of a complex series a in. a complex manner a great variety of overtones or harmonics. hese overtones or harmonics give the timbre .vhich makes up plex, and varicch In the ordinary teleyphonc, when the voice vibrations are transated into electrical undulations or waves, a

loss of character occurs, and similarly when phragm, another loss of character occurs.

however, telephone relay or repeater in the percentage of loss of character is be introduced'into the telephone circuit, such further loss of character is encountered as'to make the resulting vibrations of the receiver of such poor character as, to outweigh the advantage of amplificaobtained by the'relay or repeater. For reason, the transmission of speech through repeating or relaying mechanisms whit-.11

is not at. present commercially attempted, as

d as it would be over of us without a repeater or iithe other hand, if a relay or fundamentals upon which are superaddedand, hence, loss of character occurs.

repeater could be devised in which the percentage of loss of character was Small, the amplification of the current attained thereby would greatly extend and facilitate telephone service as enough of the character of the voice vibrations would be retained for practical purposes.

The aim of the present invention is, therefore, to provide a telephone relay or repcater in which the loss or character of the incoming electric undulations or waves shall be very small.

In the heretofore proposed telephone re.- lays or repeaters operating on the principle above-described, several diflicultics have been encountered. The first is the magnetic lag of the receiving electro-magnet or coil. This is not a very material loss, and can be practically neglected. I render this difliculty as small as possible by making the core of the electro1nag11et out of laminated soft. iron, as hereinafter described, so that the translation of the incoming electric undulations into magnetic variations will be prompt. The second and principal ditliculty heretofore encountered, I believe, is the inechan ical lag or inertia of the microphone, which forms part of the relay or repeater. The force exerted by the receiving electromagnet of the relay is, of course, very minute and only a fraction of the force of the sound- I waves originally impacting on the original transmitter. The inertia of the moving part or parts of the microphone in the relay thus becomes such retarding factor that the small magnetic variations caused by the original overtones will not actuate the n'iicrophone, More: over, 111 most forms of relayswhich have or diaphragm, the same obviously will be much more responsive to a tone which is the same or harmonically the same as the i nherent rate of vibration of the spring arm or diaphragm. Hence, not only win the. m'i 'ci'oplmnc be more resronsive to 't hls note.

been heretofore proposed, a diaph-ragnror nated. By these novel features, a relay or' I v but a persistent dominant note (which I believe is caused by this capability of the microphone to respond more readily to some particular rate or rates of Vibration) is soon struck, and a story, loud tone proceeds from the microphone, preventing the transmission of speech. This second ditticulty, I believe, is the point \vhicluhas prevented the development and introduction 0t a successful relay or l'tflhlllttl. While it is impossible to make a relay or repeater which changes the forms of energy work exactly in phase or step with the original vibrations, if the loss of character can be reduced to a small percentage, a relay or repeater can be advantageously employed. To overcome this mechanical ditliculty, have devised the fol lowing relay or repeater: The microphone of my llil: 'ovcd relay or repeater contains, as its principal novel feature, an armature which unattached and which is held in position simply by magnetic supension so as to form practically a. floating"armature, held in position only by magnetic pull. The way this. is refer-ably done is to use two separated caroon electrodes side by side, and to use an extremely li ht, delicate, reed-like armature to bridge t e space between the same, this armature thus forming with said electrodes asimultaneous double-acting microphone in which the armature is a third movable electrode. This armature is held in critical contact with said electrodes by a permanent magnet, the pull of which may be adjusted The receiving electro-ma net is placed in immediate proximity to sai armature. The armature is preferably held up against the two electrodes by the pull of the permanent magnet. B this construction, the armature is most elicutely suspended and is capable of motion by a very slight magnetic change. Further, as the said armature, by this construction, is made of extremely light weight, its inertia will be very small. Furthermore, as the armature is unattached, that is as there is no diaphragm or spring arm in the device, onelarge factor in producing the dominant tone is elimirepeater is produced in Whichthe loss 01 character is small.

In-the accompanyin two sheets of dra ings forming part 0 this applicatiorngl have shown what I now believe to be the -best way for practicing the invention, and

several modifications thereof.

Referring to said drawings, and in detail, Figure l is a cross-scctioual view of a tolehoue relay or repeater COIlHllIHZliCtl to c|ullody my invention; Big. 2 is a side yiew of the operative parts thereof; Fig. '3 is a plan View showing the construction of: no microphone; Fig. lis a plan or lace 'v' of the floating armature; 5 is a t grammatic View illustrating one way/t screw relay can be used; Fig. 6 is a front elevation, and Fig. 7, a side elevation of a modified form of relay constructed to embody my invention; and Figs. 8 and 9 are diagrammatic views illustrating different arrangements of the parts as modifications.

Referring to the drawings, and in detail, A designates a permanent magnet of the horse-shoe type. A soft iron piece B is titted to the legs thereof so as to be adjustable back and forth in the magnet. A brass-screw C having a thumb-wheel c is journaled in the apex of the magnet and is tapped into the adjustable piece B. By turning the thumb-wheel c, the )lQCG. B can be adjusted back and forth in he magnet, and thus more or less of the lines of force shunted thercthrough so that the strength of the poles can be adjusted. Secured to the poles of the permanent magnet, is an clectro-magnet E. This clectro-magnet is made u of two cores, each comprising a series 0? thin, soft iron strips secured to each pole of the permanent magnet A. The strips of soft iron are prcferabl varnished or japanned so as to be electricall insulated from each other. Electric insuliiting material is preferably arranged betw en the poles of the permanent magnet and the cores of the electro-1nagnet,'as indicated by a heavy line in Fig. 2, so as to revent short circuiting of the microphone t rough the permanent magnet, The usual. bobbins of insulated wire are placed on the cores to make up the electromagnet E, and the first circuit 10-1O is electr cally connected thereto. On the ends of the electro-mngnet bobbins are arranged electrodes 'F-F, which are preferably made of carbon. These carbon electrodes are preferably plated on their backs with metal, and wires are secured thereto which are connected to the relay or repcatiu circuit 1111. The carbon electrodes --F are referably ground ofi' smooth with the po es of the 'clectro-magnet, The electrodes F-F thus stand side by side with their \vorkiu faces inthe same plane with said poles. to two electrodes 1*-F are separated from each other so'that there is no electric connection betweenthem. Bridging the space between the said electrodes, is an armature G. This armature is preferably made of a shape just about to eover the poles of the electromagnet and the carbon electrodes F F. This armature is made out of very thin, soft iron. The same preferably has points f/ t/ bearing on the electrodes F- l to form a double microplu'mc. 'lhesc points may be little carbon pieces or may be simply humps in the armature, \iVhen the armature is made entirely outlet metal, I preferably platinum plate" .the same. Four points Sk ffg: Q are preferably used, so ,that there will be two points in contact with eachelectrode. The relay as thus constructed is preferably placed in a glaSS envelop from which the air is exhausted.

- This can be done in a convenient way by the leading-in wires of t embedding the lower part of the permanent magnet A in a glass envelop; by embedding e two circuits 10-10 and 1111 in said envelop by: ex hausting the air from saidxnveiop, and by sealing theg me as an ordinary incandescent lamp'hs sealed. 'Wh'en the relay is constructed as thus-described, the same is arranged between the' two circuits in any desired manner, as, for example, as'shown in Fig. 5, where the incoming undnlations'in a irstcircuit which contains a transmitter. are relaved or repeated into a second circuit which contains a battery and a receiver. Of course, the relay or repeater may be connected in circuit in any other desired way. \Vhen the device'is connected in circuit, the piece B is adjusted so that the armature will be brought to critical contact in the microphone. Then the incoming undulations-of the first circuit will be translated into magnetic variations by the electro-mag- 'net, which variations will be faithfully copied by the strains put on the floating armature, which thereby will actuate the microphone of the relay as said armature forms a movable elect-rode therein.

In Figs. 6 and 7, a modification is shown.

' This modification is made up of a base 12 and top 13, which are connected by screwthreadedrods 14. The rods 14; supporta hard rubber platform 15 by nuts 16, which are threaded on the rods. form carriesthe-two electrodes FF. The clectro-magnet Eg-is arranged below the microphone, and the floating armature is kept ,in position by thepermanent magnet A,

which is arranged above the microphone.

The permanent magnet is adjusted by a screw 17 to adjust the pull of the same. The screw 17 is journaled 1n the top of the electro-ma net and screw-threaded into the top 13. Tie magnet A is held from turning during adjustment by rods 18-18, which project through holes in a small vulcanite or rubber piece arrangedin the magnet. The laminated cores of the electro-magnet are held in place by a brass clamp 19.

While it is preferred to have the floating armature held up in contact with the two electrodes, so far as the broad scope of my invention is concerned, the floating armature canbe arranged above theelectrodes, as shown in Fig. 8, where the electro-magn t is shown as arranged above the same, or,

as in Fig. 9, where the electro-rnagnet-is shown as arranged below'the same. The

permanent magnet A may or may not be .used, as desired, in these modifications. The

preferred form of the device, however, is'

that shownin Figs/l and 2, or Figs. (land The said plat- 7, wherein the floating armature is held up in magnetic suspension, the lines of .force of which magnetic suspension are changed by the action of the electro-magnet.

Many other forms of devices may be constructed -to embody the principal features of my invention without departing from the broad scope thereof as expressed in the claims. 7

Havingthus fully described my invention,

what I claim and desireto secure byLetters-Ia tent is 2- 1. In a telephone relay or repeater coniprising a coil or electro-niagnet and a microphone, an unattached armature responsive .to magnetic variation arranged in the field of said coil or electro magnet for actuating the microphone.

2. In atelephone relay or repeater comprising a coil or electro-magn'et and a mi crophone, a magnetically suspended armature responsive to magnetic variation -for actuating the microphone.

3. In a telephone relay or repeater com prising a coil or electro-magnet and. a. microphone, a magnetically suspended unattached armature responsive to magnetic variation arranged in the field of and coil or 'electro-magnet for actuating the micro 4. In a telephone relay or repeater com-' prising a coil or electro-magnet and a microphone, an unattached armature arranged in the field of said coil or "electro-magnet and forming the movable electrode of the microphone.

. 5. In a'tclephone relay or repeater comprising a coil or electr'o-magnet and a microphone, having a magnetically suspended electrode otherwise free to move by gravity responsive to magnetic variation arranged in the field of said coil or electroanagnet. (3. A telephdne relay or repeater com prising a coil or electro-magpet; and a inicrophone, consisting of two electrodes, .and a third unattached electrode actuated by magnetic variation arranged in the field of said coilor electro-magnet.

.7. A telephone relay 5 or repeater' com-.

prising a coilor' electro-magnet;-' and a microphone, consisting of two electrodes and a third electrode actuated by magnetic variation held in magnetic suspension in' contact with the two electrodes.

8. A -telephone relay or repeater comprising a coil-or electro-magnet; and a microphone having two electrodes and a third unattached electrode actuated by magnetic variation held in magnetic suspension in contact witlnthe two electrodes.

9. A telephone relay or repeater mm- ,prising acoil or electro1nagnet; and a. mi-

crophone having an electrodeactuated by magnetic variation arranged in the field of said electro-magnet or coil and a permanent magnet holding this electrode magneticallysnspended in proper contact.

. 10. A'telephone relay or repeater comprising a coil or eltxrtro-magnet; and a microphone havingan electrode actuated by ma netic variation arran ed in the field of said 'electro-magnet or coi a permanent magnet holding this electrode magnetically suspendadjusting the pull of the ed, and means for permanent magnet on said electrode.

11. A t lephone relay or-repeater comprising a coif or electro-magnet; and a microphone,-ha vin'g an electrode actuated by magnetic. variation arranged in'the field of said electro-magnetor coil, a permanent magnet for holding this electrode magnetically suspend't, and an adjustable piece for adjustlng'the pull of the permanent magneton the electrode.

-12, :A telephone relay or repeater comprisin'g a'coil or electro-magnct, two electrodes,. a third electrode movable by magnetic variation arranged in the field of said coil orcelectr o-magnet, and a permanent magnet holdmg'the third electrode 1n place in'contact with the two electrodes.

13.- A telephone relay orrepeater comprising a. coil or electro-magnet, two electrodes, :1 third electrode movable by magnet ie variation arranged in the field of said coil or clectro-magnet, and a permanent magnet in line with the electro-magnet for holding the third electrode by magnetic suspension in contact with the two electrodes.

14. A telephone relay or repeater comprisng a coil or electro-lnagnet; and amicroelectro magnet and the the the side, and a third electrode bridging space between the same, the poles of electrodes being ranged in the same plane.

17. A telephd'iie relay or repeater comprising an clectro-magnet; and a microphone having two electrodes and a third electrode responsive to magnetic variation, the two electrodes being arranged inside of the poles of the electro-magnet.

18. A telephone relay or repeater comprising a permanent magnet, an electro-magnet, and a microphone hav ng a memberresponsive to magnetic variation, a glasi r -envelop for the. microphone, and means for adjusting the pull of the permanentmagnet from the outside of said envelop.

19. A tele )hone re )eater havin a receiv ing circuit. a receiving magnet, a transmitting circuit containing a variable resistance transmitting medium, and an armatured electrode connecton between-said magnet and said medium, said connection having unrestricted vibratory movement due solely to the pull of the magnet. and the weight of the said connection to transmit currentvariations from said receiving circuit to said transmitting circuit.

20. A telephone relay having a receiving circuit. a receiving magnet, a transmitting circuit, a' variable resistance transmitting medium in said transmitting circuit, and an armature electrode connecting said magnetand said medium, ranged for tree vibratory movement in a vertical direction and positioned wholly by the action of the magnet and the weight of the tll'ltltitlltt electrode member thereby to any the conductivity of said medium and to transmit current variations from said receiving circuit to said transmitting circuit.

l'n testimony whereof I have hereunto set my hand, in the presence of two subscribing witnesses.

v LOUIS \V. SOU'lHGATE. \Vitnesses Pr-nmr \V. Sot 'i'noa'rn, MARY E. Forum.

said electrode being ar- 

